Venetian blinds within double-glazed or multi-pane windows that include raise/lower and/or tilt mechanisms are known in the art. Venetian blinds of this nature typically include external magnets that are magnetically coupled to tilt and/or lift carriages disposed between the glass panes. The external magnets run along the exterior surface of the glass panes to move the tilt and/or lift carriages as a result of the magnetic coupling therebetween. Movement of the tilt carriage moves the tilt lines of the venetian blind causing the slats of the venetian blind to tilt and thereby open or close the venetian blind. Movement of the lift carriage moves the raise/lower line of the venetian blind causing the venetian blind to raise or lower. Many different tilt and/or lift mechanisms for these types of venetian blinds have been considered.
For example, U.S. Pat. No. 4,817,698 to Rossini et al. discloses a raise and lower mechanism for a venetian blind disposed between a pair of glass planes. The raise and lower mechanism includes an internal magnet located between the glass panes and an external magnet for moving the internal magnet. Cables for lifting and lowering the venetian blind extend over a pulley and are coupled to a slider that is secured to the internal magnet. The stroke of the slider is equal to the maximum extension of the venetian blind. A counterweight is provided to balance the increasing weight on the cables as the venetian blind is raised. A tilt mechanism for the venetian blind is also provided and includes an internal magnet that is located between the glass panes and an external magnet for moving the internal magnet. A helical shaft extends the length of the venetian blind and is coupled to a second shaft via an angular return transmission. The second shaft is coupled to a tilt ladder. Linear movement of the internal magnet rotates the helical shaft, which in turn imparts rotation of the second shaft. Rotation of second shaft rotates the tilt ladder causing the venetian blind to open or close.
U.S. Pat. No. Re 35,926 to Hagen discloses a raise and lower mechanism for a venetian blind disposed between two panes of glass. The raise and lower mechanism includes an external magnet that is magnetically coupled to an internal magnet positioned between the glass panes. Rotational movement of the external magnet causes the internal magnet to move. Movement of the internal magnet causes the venetian blind to raise or lower.
Japanese Patent Document No. 07-091153 to Yasushi et al. discloses a mechanism for raising and lowering a venetian blind disposed between a pair of glass panes. The raising and lowering mechanism includes a first magnet pair coupled to a shaft. The shaft is rotatable in response to movement of the first magnet pair. A second magnet pair that is magnetically coupled to the first magnet pair is disposed within an external lifting-lowering member. Linear movement of the external lifting-lowering member moves the first magnet pair to rotate the shaft. Rotation of the shaft winds or unwinds a cord thereby to raise or lower the venetian blind.
European Patent Application No. 082 723 to Anderson et al. discloses a tilting transfer mechanism for a venetian blind assembly disposed between the glass panes of a double glazing unit. The tilting transfer mechanism comprises an internal magnet located between the glass panes and an external magnet for moving the internal magnet. The internal magnet is coupled to hanger members, which support the slats of the venetian blind. Linear up and down movement of the internal magnet causes the hanger members to pivot and tilt the slats of the venetian blind thereby to open or close the venetian blind.
U.S. Pat. No. 4,685,502 to Spangenberg discloses a tilting mechanism for a venetian blind disposed between the glass panes of a double-glazed window assembly. The tilting mechanism comprises an internal magnet located between the panes and an external magnet for moving the internal magnet. Linear movement of the internal magnet imparts rotational movement of upper and lower horizontal support members via a drive element. Rotation of the upper and lower support members causes the slats of the venetian blind to tilt thereby to open or close the venetian blind.
U.S. Pat. No. 5,826,638 to Jelic discloses a tilt mechanism for a venetian blind disposed between the glass panes of a double-glazed window. The tilt mechanism comprises an internal magnet located between the glass panes and an external magnet for moving the internal magnet. The internal magnet is coupled to a tilt assembly. The tilt assembly includes a shaft that extends across the width of the venetian blind. The shaft is coupled to a tilt ladder, which supports the slats of the venetian blind. Specifically, the internal magnet is coupled to a nut that is mounted on a threaded rod. Linear movement of the nut in response to movement of the internal magnet causes the threaded rod to rotate, which in turn imparts rotation of the shaft thereby to open or close the venetian blind.
U.S. Pat. No. 6,401,790 to Dai et al. discloses a tilt mechanism for a venetian blind comprising a first magnet located between the glass panes of a double-glazed window and an external second magnet magnetically coupled to the first magnet. The first magnet is also coupled to a pulley system. Movement of the first magnet in response to movement of the external second magnet actuates a tilt ladder causing the venetian blind to open or close.
Japanese Patent Document No. 08-086167 to Takayuki et al. discloses a mechanism for operating a venetian blind disposed between the glass panes of a double-glazed window. The mechanism includes an internal magnet that is coupled by a cord to a shaft extending across the width of the venetian blind. An external magnet, which is located outside of the glass panes, is magnetically coupled to the internal magnet. A dial is provided for rotating the external magnet. Rotation of the dial and hence the external magnet, moves the internal magnet. Movement of the internal magnet actuates the cord to cause the shaft to rotate. Rotation of the shaft actuates a tilt ladder causing the venetian blind to open or close.
Japanese Patent Document No. 08-013957 to Takeshi et al. discloses a mechanism for tilting a venetian blind that is located between the glass panes of a double-glazed window. A rotatable disc is located outside of the glass panes and is coupled to a shaft via magnets. Rotation of the disc rotates the shaft. Rotation of the shaft actuates a tilt ladder causing the venetian blind to open or close.
As will be appreciated, although the double-glazed windows disclosed in the above-identified references include internal tilt and/or lift mechanisms making use of external magnets running over glass panes to actuate the internal tilt and/or lift mechanisms, problems exist. Since the external magnets are abrasive, movement of the external magnets over the glass panes often results in scratching and marking of the glass panes after extended use making the windows aesthetically unappealing.
In addition, a significant amount of force is required to overcome the coefficient of static friction between the external magnets and the glass panes when it is desired to actuate the internal tilt and/or lift mechanisms. This can result in an operator applying excessive forces to the external magnets, which may break the magnetic couple between the external magnets and the internal tilt and/or lift mechanisms. In the case of lift mechanisms, if the external magnets become magnetically de-coupled from the lift mechanisms when the venetian blind is in a fully or partially raised condition, the venetian blind may free fall to a lowered condition. This may potentially damage the venetian blind. Also, if the external magnets become magnetically decoupled from the internal tilt and/or lift mechanisms, the glass panes may be damaged when the magnet couple between the external magnets and the internal tilt and/or lift mechanism is re-established. Moreover, since the external magnets and the tilt and/or lift mechanisms are usually concealed, re-establishing the magnetic couple between the external magnets and the tilt and/or lift mechanisms can prove to be difficult.
In the case of lift mechanisms, the pull ratio of the lift mechanisms is typically one-to-one. Thus, for every inch the venetian blinds are to be raised, the external magnets must be moved along the glass panes an equal distance. In the case of large multi-pane windows that accommodate correspondingly large venetian blinds, reaching and moving the external magnets the required distances to raise the venetian blinds to fully open conditions can be difficult, especially for elderly people, children, short people or people with back problems. As will be appreciated, improvements in magnetically actuatable mechanisms to raise/lower and/or tilt a venetian blind disposed between the glass panes of a multi-pane window are desired.
It is therefore an object of the present invention to provide novel magnetic tilt and raise/lower mechanisms for a venetian blind and novel multi-pane windows incorporating the same.